Athletes engage in strenuous training to accomplish the goals of their sport. This strenuous training essentially amounts to trauma to the body, in that the human body interprets every strenuous work-out as a threat to its survival. It is known that muscle damage, caused by excessive training, releases the catabolic hormone prostaglandin-E2. Strenuous exercise also causes the release of adrenocorticotropin (ACTH), which is a pituitary hormone. The presence of increased levels of ACTH increases the production of the catabolic hormone cortisol. Cortisol is also known as hydrocortisone, which is a glucocorticoid of the adrenal cortex that is a derivative of cortisone which is used in the treatment of rheumatoid arthritis. Thus, cortisol is a naturally occurring anti-inflammatory steroid. This catabolic hormone results in the release of amino acids from muscle tissue and prevents absorption of glucose. Cortisol, as a catabolic stress hormone, cannibalizes muscle tissue. High cortisol levels also result in the breakdown of connective tissue, lowered immunity and reduced muscle RNA synthesis. While cortisol may be a detriment to the athlete, scientists have conjectured that when the human body is stressed or traumatized, it triggers a "fight or flight" survival response. The biological design of cortisol is such that when a human is threatened, cortisol levels rise and mobilize the body for action by breaking down fat and muscle stores for emergency energy. Cortisol also reduces swelling in the event of injury. After the threat or trauma has subsided cortisol levels return to normal. The cortisol-stress relationship is designed for intermittent physical threats and not the constant stimulation provided by today's aggressive athletes. Ongoing training results in cortisol levels that do not return to normal for extended periods of time and thereby result in the breakdown or loss of muscle tissue.
After strenuous exercise, muscle tissue enters a stage of rapid nitrogen absorption in the form of amino acids and small peptides in order to rebuild the muscle fibers, grow and add new muscle fibers. During this period of repair and growth, it is important that the muscle cells have available to them sufficient levels of nitrogen in the form of amino acids.
Exercise is the repeated use or activity of a muscle group or organ. Exercise is bodily exertion for the sake of developing and maintaining physical fitness. Anaerobic exercise occurs when the activity results in the body incurring an oxygen debt. In contrast, aerobic exercise is physical conditioning involving exercise that does not cause an oxygen debt, such as distance running, jogging, walking, swimming, circuit training or cross country skiing strenuously performed so as to cause a marked, but steady increase in respiration and heart rate over an extended period of time. The most familiar form of anaerobic exercise is weightlifting; but handball, football and tennis are other examples.
Athletes that overtrain sometimes enter into a catabolic state. Muscle catabolism occurs when the athlete enters a negative nitrogen balance. People on diets usually have a negative nitrogen balance and therefore lose muscle tissue when they lose weight. In contrast, a positive nitrogen balance means the animal has enough nitrogen left over to synthesize muscle proteins.
The caloric requirements of a mammal are dependent upon the energy expenditure of the mammal. A hypocaloric diet is one that is under or less than the energy expenditure of the mammal. The typical weight loss diet is hypocaloric, thus the body will use energy stores such as fat and muscle tissue to make up the difference between the energy content of the diet and the energy expended. Thus, the animal will lose weight. In contrast, a hypercaloric diet will supply an amount of energy beyond that required for a given level of activity. In such a situation, the body will store the excess energy in the form of fat and/or muscle tissue. In the usual circumstances, the excess energy will be deposited as adipose tissue or fat.
The present invention is based in part, upon the discovery that the use of pyruvate in combination with anaerobic exercise, produces a synergistic effect in increasing the muscle tissue of a mammal while at the same time increasing the metabolism of fat in the body.
As used herein and the claims, the term "pyruvate" means any salt or ester of pyruvic acid. Pyruvic acid has the formula: ##STR1##
Pyruvic acid is a colorless liquid with an odor resembling that of acetic acid and has a melting point of 13.degree. C. Pyruvic acid is an intermediate in the breakdown of sugars to alcohol by yeast. The mineral salts of pyruvic acid, such as magnesium pyruvate, potassium pyruvate or calcium pyruvate or mixtures thereof are useful in the present invention. Sodium pyruvate is not especially preferred as it is known that sodium is associated with various negative medical conditions such as high blood pressure, water retention and heart disease. Further, certain athletes, such as bodybuilders, desire to present a defined visual image of their body which shows muscle definition and thus, the water retention properties of the sodium salt are not beneficial. Pyruvate precursors in the form of pyruvamides or pyruvyl-amino acids are also useful in the present invention. Pyruvyl-glycine is representative of the useful pyruvyl-amino acids. Another form of pyruvate precursor is pyruvyl-creatine, wherein pyruvate is bonded to creatine either covalently or ionically. Creatine or methylguanidineacetic acid has the chemical formula: ##STR2## and is present in the muscle tissue of vertebrates. It plays an important part in the cycle of chemical changes involving muscular contraction. Normally, creatine is the form in which creatine is excreted. Creatine is formed in the body by the methylation (by methionine) of glycocyamine.
Pyruvate has a number of known useful applications in medicine. Pyruvate in combination with other compounds has been described for retarding fatty deposits in livers (U.S. Pat No. 4,158,057); for treating diabetes (U.S. Pat. No.4,874,790); for retarding weight gain (U.S. Pat. Nos. 4,812,879, 4,548,937, and 4,351,835); to increase body protein concentrations in a mammal through decreasing the deposition of fat (U.S. Pat. No. 4,415,576); for treating cardiac patients to increase the cardiac output without accompanying increase in cardiac oxygen demand (U.S. Pat. No. 5,294,641); for extending athletic endurance (U.S. Pat. No. 4,315,835); for retarding cholesterol increase (U.S. Pat. No. 5,134,162); for inhibiting growth and spread of malignancy and retarding DNA breaks (U.S. Pat. No. 5,612,374) and for inhibiting generation of free radicals (U.S. Pat. No. 5,480,909). All of these references are incorporated herein by reference.
U.S. Pat. No. 4,981,687 relates to compositions and methods for achieving improved physiological response to exercise. More specifically, this patent discloses a beverage comprising water, sugar, electrolytes, glycerol and pyruvate; and its use to ameliorate the effects of physical exertion. The teachings of U.S. Pat. No. 4,981,687 are incorporated herein by reference.
U.S. Pat. No. 5,089,477 discloses the use of pyruvate in a liquid composition that is used to prevent weight loss in agricultural animals resulting from dehydration.
U.S. Pat. No. 5,147,650 and U.S. Pat. No. 5,238,684 discloses and claims a fluid composition comprising water, electrolytes, sugar, glycerol, lactate and pyruvate. The teachings of U.S. Pat. Nos. 5,147,650 and 5,238,684 are incorporated herein by reference.
U.S. Pat. No. 5,236,712 discloses and claims a beverage containing water, electrolytes, pyruvate and alanine in a concentration of from about 0.5% to about 10%. The teachings of U.S. Pat. No. 5,236,712 are incorporated herein by reference.
Pyruvate in various forms has been proposed for enteral administration and for parenteral administration. Typically, pyruvates are available in the form of salts, for example, calcium pyruvate and sodium pyruvate. U.S. Pat. Nos. 5,283,260 and 5,256,697 disclose uses for the pyruvyl-amino acids and methods for their production.
Pyruvate has been administered to mammals enterally or parenterally typically at superphysiological levels. The amount of pyruvate administered generally ranges from 0.5 to 20% of the mammal's daily caloric intake. For a 2,000 calorie diet, this would range from 2.5-100 grams per day of pyruvate. For enteral consumption, the pyruvate may be disbursed or dissolved in a beverage product or may be included in cookies, candies or other foods. Pyruvate may also be introduced as an aqueous solution parenterally.
Protein supplementation for serious athletes, such as body builders, is well accepted and is well known to increase the muscle mass of the athlete. Typically recommended dosages range between 2.0 and 3.5 gms of quality protein per kilogram of body weight per day. Numerous sources for the protein supplements are known, such as milk, egg, soy, beef and vegetable protein. Isolated fractions of these sources are also known such as ion-exchange whey protein, caseinates, whey protein concentrates, immunoglobulin and egg albumin. Protein supplements typically are provided as powders. It is also known to provide protein supplementation in the form of peptides (hydrolyzed protein) or even free amino acids. These approaches have two major limitations; cost and taste.
There are more than 600 skeletal muscles in the body. Skeletal muscles are also called "voluntary muscles" because they are responsible for purposeful movement of the body such as running and jumping. The brain sends signals to each and every skeletal muscle fiber enabling us to perform actions when we wish to do them.
There are three (3) different types of muscle in the body: skeletal muscle, smooth muscle and cardiac muscle. All three types of muscle are composed of fibers that permit movement through coordinated contraction and relaxation. At the microscopic level, the three types of muscle share a common mechanism for contracting. The basic working elements are actin and myosin filaments. When a muscle contracts, the individual myosin filaments slide over the actin filaments, much like an extendable ladder does when it closes. This causes the overall length of the muscle to shorten. One surprising aspect of the present invention is that a special mixture of potassium and calcium salts of pyruvate can be effective in increasing the muscle mass in a mammal when consumed in conjunction with anaerobic exercise.
In view of the present disclosure or through the practice of the present invention, other advantages or solutions to other problems will become apparent.